A266048 Number of n X n integer arrays with each element equal to the number of horizontal and antidiagonal neighbors less than or equal to itself.

1, 7, 20, 4203, 27764427, 162959704686, 7819198018954698, 8592495369531464281394, 61644092749139641953624493469, 2207027264659323985934603717331920405

Offset

1,2

Comments

Diagonal of A266055.

Links

R. H. Hardin, Table of n, a(n) for n = 1..11

Example

Some solutions for n=4
..1..1..3..0....0..1..3..0....0..3..0..1....0..3..0..2....1..0..3..0
..2..1..4..0....2..0..3..0....0..4..2..0....0..4..2..0....2..1..4..0
..0..3..1..2....1..4..2..2....0..4..2..0....0..4..3..0....0..3..2..2
..0..3..1..0....0..3..1..1....0..3..2..0....0..3..2..0....0..3..0..1

Crossrefs

Cf. A266055.

Sequence in context: A300308 A344849 A216457 * A233331 A158280 A201072

Adjacent sequences: A266045 A266046 A266047 * A266049 A266050 A266051

Keyword

nonn

Author

R. H. Hardin, Dec 20 2015

Status

approved